package state;

import bean.SensorReading;
import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.streaming.api.checkpoint.ListCheckpointed;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;

import java.util.Collections;
import java.util.List;

public class StateTest1_OperatorState {

    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        env.setParallelism(1);

        DataStreamSource<String> inputStream = env.socketTextStream("192.168.45.132", 7777);

        SingleOutputStreamOperator<SensorReading> dataStream = inputStream.map(line -> {
            String[] fields = line.split(",");
            return new SensorReading(fields[0], new Long(fields[1]), new Double(fields[2]));
        });

        SingleOutputStreamOperator<Integer> resultStream = dataStream.map(new MyCountMapper());

        resultStream.print();
        env.execute();

    }

    private static class MyCountMapper implements MapFunction<SensorReading, Integer>, ListCheckpointed<Integer> {

        // 定义一个本地变量，作为算子状态
        private int count=0;

        @Override
        public Integer map(SensorReading sensorReading) throws Exception {
            count++;
            return count;
        }

        @Override
        public List<Integer> snapshotState(long l, long l1) throws Exception {
            return Collections.singletonList(count);
        }

        @Override
        public void restoreState(List<Integer> list) throws Exception {
            for(Integer num: list){
                count+=num;
            }
        }
    }
}
